1. Oberlin College Oberlin Ohio
2. Department of PediatricsUniversity of California, San Diego La Jolla California
3. California Preterm Birth InitiativeUniversity of California San Francisco San Francisco California
4. Department of Obstetrics, Gynecology and Reproductive SciencesUniversity of California San Francisco San Francisco California
5. Department of PediatricsUniversity of California San Francisco San Francisco California
6. Department of Epidemiology and BiostatisticsUniversity of California San Francisco San Francisco California